Chrysler
Type:
    Powertrain - Fuel and Air Metering - ISO/SAE Controlled
Description:
    HO2S Shorted to Voltage Conditions
Cause:
    Engine runtime 2-4 minutes, ECT sensor input 176-180°F, then the test started and the PCM detected that the front HO2S-21 signal was more than 1.2-1.5v for over 2.6 seconds.

Generic
Type:
    Powertrain - Fuel and Air Metering - ISO/SAE Controlled
Description:
    O2 Sensor Circuit High Voltage

GM
Type:
    Powertrain - Fuel and Air Metering - ISO/SAE Controlled
Description:
    HO2S Circuit High Input Conditions
Cause:
    No CKP, ECT, EGR, EVAP, Fuel Trim, Fuel Injector, IAT, MAP, Misfire or TP sensor codes set, throttle angle from 5-40%, closed loop A/F ratio from 14.5-14.8, then the PCM detected that the HO2S-21 signal remained over 975 mv in closed loop, or that the signal remained below 200 mv in Decel Fuel Cutoff mode

Nissan
Type:
    Powertrain - Fuel and Air Metering - ISO/SAE Controlled
Description:
    Heated oxygen sensor (HO2S) 1, Bank 2 - voltage high
Cause:
    Wiring, HO2S, fuel system, injector, ECM